Valve-operating mechanism



Aug. 4, 1925.

J. G. WOOD VALVE OPERATING MECHANISM Original Filed D. 11, 1922 INVENTOR. .75/777 G. ifiaal,

Patented Aug. 4, 1925. v A

UNITED stares earner rice;

JOHN G. WOOD, OF IHDIANAPOLIS,;INDIANA, ASSIGNOR TO ALON'SO'N P. BRUSH, OF

DETROIT, MICHIGAN.

VALVE-OPERATING MECHANISM.

Application filedDecember 11, 1822, Serial No. 606,269; Renewed September 24, 1924.

To all whom itmag concern: Be it known that 1, JOHN G. lYooD, a c1t1- zen of the United States, residlng at Indianapolis, in the county of Marion and In the operation of the valve mechanism of internal combustion engines of the poppet-valve type, it is necessary that a slight lostanotion be provided, of a few thousan'dths of" an inch, to make certain that the valve will surely be seated under all tempen ature conditions which may exist in opera tion, and in spite of unequal expansion of the various parts. Although this lost-motion is ve'ry'slight, itpermits a certain slap or knock of some of the parts, and this knock canbe heard inthe operation of the engine;

Itis-the' main object of my present invention to eliminate this sound, and thereby make the engine quieter, and especially to do so in the typeof engine embodying overhead valves with a rocker arm of the socalled rocking-chair type, in which the rocker arm is not-carried on a pivot pin but is rocked or rolled on a. support. Itis a further object of my invention to makeiit easier to shape the bearingsurface of the V rocker" arm where it engages its fulcrum support. I

In carrying out my. invention, I provide at the place where'the slap or knock may occur, and most" particularly at the fulcrum support for the rocker arm, an'insertedbearing member which isnot metallic, but 1nstead is made-up of some"sound-destroying materiall This sound-destroying material may be suitably shaped to get the' desired rocker-arm action; and as the shaping may be done apart from the rocker arm, it may be done much moreeasily than is otherwise possible. A number of non-metallic materials may be used, but the material I prefer is made up of a" plurality of superposed layers of fabric impregnated with and bound together by phenoliocondensate varnish; as I havefound that thismakesa material which is properly and easily workable to the desired shape, and whichla'rgely if notwholly eliminates the noise of operation.

The accompanying drawing illustrates i my invention-z Fig. 1 is a" fragmentary View,

partly in section, of a rocker-arm mecha-- half-sectional, half-elevational view of one of the lm'prcgnated-fabric buttons used; and

Fig. 3 is a perspective view of suchbutton, 1n about its natural size.

The valve stem 10 may be-of any ordlnary type, with the usual valve (not shown) at its lower end, and is spring-pressed upward to closed positionby any suitable compres sion spring 11. A- valve push-rod 15 is mounted for vertical reciprocation in the usual manner, as by a cam (not shown), and is usually parallel to the valve-stem 10. The push-rod 15 acts on thevalve-stem lO through a rocker arm 16. In the rockingchair type of valve operating mechanism in connection with which I have illustrated my invention, and to which the invention is particularly applicable, this rocker arm near its two endshas on itsunder' face two down wardly' convex curved surfaces 1 and 18, which cooperate with and bear upon the upper end of tlie valvestem 10 and push-rod 15 respectively. These convex surfaces 1 7- and 18' are cylindrical surfaces, which roll on the-ends of their associated valve stem and push-rod respectively. The upper side of the rocker arm 16 has a pocket 19, into which projects downwardly an adjustable fulcrum screw 20 carried by and vertically adjustable in a suitable stationary support 21 fixed on the frame ofthe engine. The lower'end of the fulcrum screw 20is a plane surface, perpendicular to the axis ofthe screw adjustment, and this plane surfacecooperates with an upwardly convex surface 22 located within the pocket 19 and fixed with'relation to the rocker arm 16. This surface 22 is also a cylindrical surface, simi lar tothesurfaces 17 and 18, but isconvex upward instead of being convex downward, so that it will roll on the plane end face' of the fulcrumscrew 20 as: therocker arm 16 rocks.

p In order to prevent-relative-displacement between the rocker arm' and its associated parts, the upper e'nd ofthe valve:rod 15' and tli'e lower 'end-of the fulcrum-screw 20-ar e provided with axially extending holes 23 and 24 respectively, which may be simple cylindricalholes; and pins 25 and 26 are mounted in the rockera'rm and project intosaid holes respectively. The heads of the pins 25 and 26 are preferably circular in cross-section, and are curved axially, something like a gear-tooth addendum, being larger at their bases where they abut against the rocker arm than at any other point. 'By

thus shaping the heads of the pins 25 and 26,

. guide flanges 27 from the under face of the rocker arm 16 on the two sides of the upper end of'the valve stem 10, as is clear from Fig. 1. These guide flanges do not interfere with the co-operation of the surface 17 with the upper end of the valve stem.

The valveoperating mechanism so far de scribed is not my invention, but is merely the preferred form of valve-operating mechanism to which I contemplate applying my invention. lVith this valve-operating mechanism as so far described, there would be a certain amountof slap or knock; due to the fact that to ensure thecompleteclosing of the valve on the, lower end of the valve stem when the latter is raised, under all temperature conditions which may be en countered, it is necessary to let .the pushrod descend a very, slight distance farther downward thanwould be necessary for, the bareclosing of such valve; and this results in letting the rocker arm 16 ,as a whole drop slightly when the valve is closed to produce a very slight separation between the surface 22 and the lower plane end of the fulcrum screw 20. Because of this separation, there.

is a slight slap or knock when these two surfaces are re-engaged upon the next upward movement of the valve push-rod15.

To avoid this slap or knock,and also. .to make it possible to machine the surface 22 more easily than if it were originally at the bottom of the'pocket 19, I provide such surface 22 on a non-metallic button 30, which is originally separate from the rocker arm but is pushed into the pocket 19 after first being completely machined. This button has a central hole 31 for allowing the projection therethrough'of the pin 26, which said button surrounds. The upper surface of the button thus forms the surface 22, which may be machined. easily before the button has been put into the pocket. The button 30 is held in proper position in the pocket by an eccentrically located dowel pin. 32, which prevents the button from turning and holds it in position so that its upper surface 22 curves in the plane desired. By having this button 30 of non-metallic material, the metallic slap or knock which is otherwise caused when the rocker,arm 16 is lifted upon The material for the button 30* and the bushing 35 may be of anumber of non-metallic substances. The material .I prefer,

however, is a built-up material made from layers of fabric, such as canvas, impregnated with a synthetic resin, preferably phenoliccondensate varnish, which serves as a binder to unite the several layers of. fabric into a unit capable of being worked very readily and accurately. After the phenolic-condensate varnish which impregnates the fabric has hardened, the material is cut into buttons 30 of the desiredshape, or into the bushings 35, and these are machined in the desired forms, with the desired surface 22 on the button 30, and the necessary eccentrically located hole 36 forreceiving' the dowel pin The shape ofthe button 30 need not be round, although that isthe most convenient shape; but such shape and the shape of the pocket 19 ma be anythlngdesired. The button 30 an the bushing 35 are fully machined separately from the rocker arm, and put in place therein when complete.

I claimas my invention r 1. In a valve-operating mechanism for 1nternal combustion engines, the combination of a rocker arm, said rocker arm having a pocket at an intermediate point, a fulcrum projecting into said pocket to form abearing for said rocker arm, a button of nonmetallic material fixed in the bottomzof said pocket and on which'said fulcrum bears, and a valve stem and a. push rod cooperating with said rocker arm. i

2. In a valve-operating mechanism for internal combustion engines, the combination of a rocker'arm, said rockerarm having a pocket at an intermediate point, a fulcrum projecting into said pocket to form abearing for said rocker arm, a button fixed in the bottom of said pocket and on which said fulcrum bears, said button being formed of a plurality of layers of fabric impregnated with and bound into a unit by a resinous binder, and a valve stem and a push rod 00- operating with said roclrer arm.

3. The combination set forth in claim 1, wherein the button-surface which engages the fulcrum is convexly cylindrical to roll on the fulcrum as the rocker arm rocks.

4. In a valve-operating mechanism for in ternal combustion engines, the combination of a rocker arm, said rocker arm having a pocket at an intermediate point, a fulcrum projecting into said pocket to form a bearing for said rocker arm, a button fixed in the bottom of said pocket and on which said fulcrum bears, and a valve stem and a push rod co-operating with said rocker arm, the button surface which engages the fulcrum being convexly cylindrical to roll on the ful crum as the rocker arm rocks.

5. The combination set forth in claim 2, wherein the button-surface which engages the fulcrum is convexly cylindrical to roll on the fulcrum as the rocker arm rocks.

6. In a valve-operating mechanism for internal combustion engines, the combination of a rocker arm, said rocker arm having a pocket at an intermediate point, a fulcrum projecting into said pocket to form a bearing for said rocker arm, a button fixed in the bottom of said pocket and on which said fulcrum bears, a valve stem and a push rod co-operating with said rocker arm, the bearing face of the fulcrum having a hole in it and said button having a hole through it, and a pin projecting from the base of said pocket through the hole in the button and into the hole in the bearing face of the fulorum.

7. In a valve-operating mechanism for internal combustion engines, the combination of a rocker arm, a fulcrum for said rocker arm, and a Valve stem and a push rod co-operating with said rocker arm, said rocker arm having a rolling bearing on the end of one of said two last-named parts, such end being provided with a longitudinal hole, a bushing of non-metallic material forming a lining for such hole, and a guide pin projecting from the rocker arm into such hole.

8. In a valve-operating mechanism for internal combustion engines, the combination of a rocker arm, a fulcrum for said rocker arm, and a Valve stem and a push rod c00pcrating with said rocker arm, said rocker arm having a rolling bearing on the end of one of said two last-named parts, such end being provided with a longitudinal hole, a bushing of non-metallic material forming a lining for such hole, and a guide pin pro jecting from the rocker arm into such hole, said bushing being formed of a pluralityof layers of fabric impregnated and bound into a unit by a resinous binder.

In witness whereof I, JOHN G. WOOD, have hereunto set my hand at Indianapolis, Indiana, this 7th day of Dec, A. D. one thousand nine hundred and twenty two.

JOHN G. WOOD.

Certificate of Correction.

It isihereby certified that the name of the assignee in Letters Patent No. 1,548,401, granted August 4, 1925, upon the application of John G. Wood, of Indianapolis, Indiana, for an improvement in ValW-Operatim Mechanism, was erroneously Written and printed as Alonson P. Brush, Whereas said name should have been Written and printed as Alamson P. Brush, as shown by the records of assignments in this ofiice, and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 1st day of September, A. D. 1925.

[SEAL.] KARL FENNING,

Acting Commissioner of Patents. 

